Abstract: A system and a method for measuring creep of a hydro-generator are provided. In the system, circle of “sawtooth waveform” ribbon is arranged around an outer wall of a main shaft of a hydro-turbine, a “sawtooth waveform” of the ribbon is formed by arranging isosceles right triangles, a hypotenuse of the isosceles right triangle forms a straight line segment, the isosceles right triangle is painted with a color code, a camera is arranged directly opposite to the main shaft of the hydro-turbine, and the camera takes an image of the ribbon and images on an imaging plane at a back end. The main shaft of the hydro-turbine is continuously photographed and sampled with an image, the image processing terminal extracts feature quantities on a reference image and a current image, calculates a creep angle of a set, and sends out an alarm signal when it reaches an alarm value.